configure: Explicitly check for sleep
Bugfix: configure: Use new need_lowl_vcom instead of need_fpgautils
Move unused winsock2.h includes to the end of config.h

winsock2.h must be included before windows.h, but windows.h is included by various standard C headers
Bugfix: Set LIBUSB_LIBS for non-pkgconf non-header-subdir libusb installations
Workaround bug in MinGW-w64: Check for strtok_r to be defined at compile-time, and don't override it unless we really want to override

MinGW-w64 #defines strtok_r in pthread.h instead of string.h where it's supposed to be (causing the configure check to fail)
This workaround has a limitation: it could result in two different files using different strtok_r implementations; if so, and they share saveptr, it's possible the two implementations may work differently and conflict in their understanding of saveptr
Merge commit 'cd61807' into bfgminer
Merge branch 'uniscan2' into bfgminer
Merge commit 'ba3dae8' into bfgminer
configure: Put configuration options summary back after everything completes
configure: Condense configuration options summary a bit